>I use Ultra VNC for customer support.

>How do I find a DSL Broad band user's IP address to connect to him(as DSL IP is hidden)?

I eat my words. Ultra VNC has a solution for it. It has NAT to NAT connectivity, or Port Forwarding and a single click Solution maker Kit.

Ultra VNC has a solution for it all... check it out http://ultravnc.sourceforge.net/addons/singleclick.html